have a buddywho has no power getting to the compressor has checked fuses and wireing but has come up empty handed ,need help. truck is an 05 4x4 auto

 

If the A/C system has a leak and the R-134A has leaked out then the clutch will not engage. There is a sensor switch in the high side of the refrigerant system to prevent the A/C clutch from operating if the system has lost it's charge or if the charge is too low.
Check to see if it still has a freon charge before chasing electrical problems.